Category: aurora

Scientists Solve The Mystery Of STEVE, And Fin…

Scientists Solve The Mystery Of STEVE, And Find It’s So Much More Than An Aurora

“Normally, aurorae are produced by the Sun’s charged particles striking the atoms in Earth’s upper atmosphere. The solar wind particles get bent by Earth’s magnetic field, exciting and ionizing oxygen, nitrogen, and hydrogen. When electrons recombine with ions, they cascade back down to lower energies, creating aurorae from their emission lines. STEVE is distinct from this for multiple reasons.”

It isn’t often that a naked-eye skywatcher gets a chance to observe an entirely new optical phenomenon that’s never been seen or recorded before. Yet earlier this century, that’s exactly what’s happened with a purple/green/mauve ribbon of light that sometimes appears in the sky. Known as STEVE, for strong thermal emission velocity enhancement, this ribbon includes colors never seen in an aurora, appears at lower latitudes than those where aurorae are typically found, and most importantly, isn’t created coincident with the precipitation of charged particles. In other words, it’s an entirely new phenomenon!

The mystery of what creates STEVE has now been solved, and it’s not only a great scientific story, it’s also beautiful to behold. Come see the full story (and some great photos and videos) today!

just–space:

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The Aurora and the Sunrise : On the International Space Station (ISS), you can only admire an aurora until the sun rises. Then the background Earth becomes too bright. Unfortunately, after sunset, the rapid orbit of the ISS around the Earth means that sunrise is usually less than 47 minutes away. In the featured image, a green aurora is visible below the ISS – and on the horizon to the upper right, while sunrise approaches ominously from the upper left. Watching an aurora from space can be mesmerizing as its changing shape has been compared to a giant green amoeba. Auroras are composed of energetic electrons and protons from the Sun that impact the Earth’s magnetic field and then spiral down toward the Earth so fast that they cause atmospheric atoms and molecules to glow. The ISS orbits at nearly the same height as auroras, many times flying right through an aurora’s thin upper layers, an event that neither harms astronauts nor changes the shape of the aurora. via NASA

How Science Creates (And You Can See) The Best…

How Science Creates (And You Can See) The Best Aurora Shows On Earth

“It surprises a lot of people who’ve seen still photos of the aurora when they see it for themselves, with their own eyes, for the first time. Auroral displays aren’t static, but rather move quite quickly, like a green, diffuse curtain being pulled and swirled across the sky. The best views of the aurora — and I hate to say it, because most of us will never experience it firsthand — is from above the Earth’s atmosphere, in outer space.

But the second best place to view the aurora is from anyplace within about 30 degrees of the Earth’s magnetic pole. This includes much of northern Canada and Russia, northern Norway, Sweden and Finland, as well as all of Iceland, Greenland, and (in the south) Antarctica. Even without a spectacular solar event to coincide with them, aurorae in these locations are commonplace. Although you can see them at any time of the year, the best time to view them is in the winter, when you have the greatest number of hours of darkness, when you’re coincidentally experiencing clear skies.”

The Sun emits charged particles, in the form of the solar wind, on a continuous basis. Our Earth’s magnetic field deflects most of them away, but when magnetic field lines connect between the Sun and Earth, particles get funneled down into rings around the poles. A coronal mass ejection or solar flare can greatly enhance this, leading to the most spectacular auroral displays human eyes have ever laid sight upon. There are a slew of great locations around the world where you can see them, and I’ll be leading an expedition to one of them, Iceland, next January.

Whether you’ve ever seen them (or are headed to see them) or not, you won’t want to miss the incomparable sights and science of the best aurora shows on Earth!